Name of Learner: __________________________________
Grade Level: _____________
Section: __________________________________
Date: ______________
KINETIC ENERGY
Background Information for Learners
When the moving object is faster, the KE is greater. As an example, there are
approximately 20 typhoons pass over the Philippines each year. Since typhoons are
characterized by high-speed winds, they have Kinetic energy that make them capable of
doing a lot of “work” on anything in their way.
Kinetic Energy can be transferred from one moving object to another and is
dependent on an object’s speed or velocity and mass.
It is given by the equation as:
KE= mv2
2
Where:
KE = Kinetic Energy (J)
m= mass (kg)
v= velocity (m/s)
The equation implies for KE also implies that KE is directly proportional to the
square of the speed of the object. Thus, when an object doubles its speed, its Kinetic
Energy quadruples or increases 4 times. Let us determine the factors affecting Kinetic
energy by studying the sample problems.
Effects of mass and velocity to Kinetic Energy
Sample Problem 1:
What is the Kinetic energy of the two vehicles, namely: Car A having a mass of 5000
kg and car B with 10,000 kg of mass travelling at the same speed of 50 m/s?
Note: Follow the Steps below.
Steps in
Solving the
problem
Identify
the Given
given from the
problem
What
is Required
component
is
being asked?
Write
the Equation
correct equation
Substitute the Solution
given
values
using
the
equation
Car A
Car B
Mass = 5000 kg
Speed (v) = 10 m/s
Mass = 10, 000 kg
Speed (v) = 10 m/s
KE
KE
KE= mv2
2
KE = 5000kg (10 m/s)2
2
KE = 5000Kg (100 m2/s2)
2
KE= mv2
2
KE = 10, 000kg (10 m)2
2
KE = 10, 000kg (100 m2/s2)
2
KE = 500, 000 kgm2/s2
2
KE = 1, 0000, 000 kgm2/s2
2
Write
your Answer
answer and the
KE = 250, 000 J
KE = 500, 000 J
correct unit
The KE of the two different mass vehicles when the same speed is different from
each other. When the mass of an object is increase or doubled, its KE energy also increased
or doubled. Therefore, factor affecting the KE is mass.
Sample Problem 2:
How about when two vehicles of the same mass of 5,000 kg moving at different
speed 10 m/s and 20 m/s, respectively.
Steps in
Solving the
problem
Identify
the Given
given from the
problem
What
is Required
component
is
being asked?
Write
the Equation
correct equation
Substitute the Solution
given
values
using
the
equation
Write
your Answer
answer and the
correct unit
Car A
Car B
Mass = 5000 kg
Speed (v) = 10 m/s
Mass = 5000 kg
Speed (v) = 20 m/s
KE
KE
KE= mv2
2
KE= mv2
2
KE = 5000kg (10 m/s)2
2
KE = 5000Kg (100 m2/s2)
2
KE = 500, 000 kgm2/s2
2
KE = 5000kg (20 m/s)2
2
KE = 5000Kg (400 m2/s2)
2
KE = 2,000, 000 kgm2/s2
2
KE = 250, 000 J
KE = 1, 000, 000 J
Based on sample problem number 2, if the speed is doubled, the KE is
increased four times. If the speed is reduced by ½ with the same mass, then its KE
is reduced by ¼. If the speed of an object is tripled, then its KE is 3 times higher
or greater. Therefore, another factor that affect the KE is speed or velocity.
Learning Competency with Code
Identify and explain the factors that affect potential and kinetic energy (MELC Week
2-3)
Directions/ Instructions
Read and understand the instructions for each activity given below. Answer
the questions that correspond to each item/number. Write your answers on the
space provided.
Activity 1 – Choose the right one!
Instruction: Encircle the correct underlined word to complete the statements.
1. The kinetic energy of a 10,000-kg vehicle is twice as much as the kinetic energy of
a 5,000-kg vehicle when both are travelling at the different or same speed.
2. The kinetic energy of a car travelling at 10 m/s is four times the kinetic or
potential energy of a car travelling at 5 ms/s.
3. When an object’s speed doubles, its kinetic energy doubled or quadrupled.
4. When an object’s mass doubles, its kinetic energy also doubled or reduced by ½.
5. The factors affecting the KE are mass and height or mass and velocity.
Activity 2 – Analyze Me!
A. Instruction: Analyze the data below about the Kinetic Energies of different vehicles
and answer the guide questions that follows it.
Vehicles
mass
Speed
Motorcycle
1000 kg
10 m/s
Car
5000 kg
10 m/s
Truck
10000 kg
10 m/s
Guide Questions:
1. Which of the vehicles has higher KE? _______________________
2. What is your reason for your answer number 1? ______________________________
3. What do you think is the reason why the different vehicles have different KE
with the same speed? _______________________________________________________
____________________________________________________________________________
B. Instruction: Analyze the data below about the Kinetic Energies of the same vehicles
with the same mass but different speed and answer the guide questions that follows
it.
Vehicles
mass
Speed
Car A
5000 kg
10 m/s
Car B
5000 kg
20 m/s
Car C
5000 kg
30 m/s
Guide Questions:
1. Which of the vehicles has higher KE? _______________________
2. When the speed of Car A is doubled, what will be its KE?
______________________________
3. What do you think is the reason why the 3 vehicles with the same mass have
different KE? ___________________________________________________________
Activity 3 – Try to Solve Me!
Instruction: Read and understand the problem regarding Potential energy and solve the
problem using the step by step process. (Please refer to the sample problem in the
discussion part for your guide)
Problem Compute the KE of a 1500 kg car traveling from 5 m/s to 10 m/s.
Steps
Identify the
Given
Mass = 1500 kg
Mass = 1500 kg
given from
Speed (v) = 5 m/s
Speed (v) = 10 m/s
the problem
What is
Required
component is
KE
being asked?
Write the
correct
equation
Equation
Substitute
the given
values using
the equation
Solution
Write your
answer and
the correct
unit
Answer
KE= mv2
2
KE = 1500kg (5 m/s)2
2
KE = 1500kg (25 m2/s2)
2
KE = 37, 500 kgm2/s2
2
KE = 18, 750 J
Learner’s Reflection
_______________________________________________________________________________________
_______________________________________________________________________________________
_______________________________________________________________________________________
_______________________________________________________________________________________
Parent’s/Guardian’s Signature: _______________________________________________________
Prepared by:
GERALDINE A. LAPIGUERA
References
Books
Campo, Pia C., et.al.Science Learner's Module 8. Pasig City: Department of Education, 2016.
Science – Grade 8 Alternative Delivery Mode Quarter 1 – Module 3: Potential Energy and
Kinetic Energy First Edition, 2020
PENG-AS, LARRY A., Potential and Kinetic Energy- Learning Activity Sheet in Science 8,
Quarter 1-Week 3.
Teaching Modules. Force, Motion, and Energy. Grade 8, Department of Science and
Technology, Science Education Institute, 2021.
Website
“Kinetic
and
Potential
Energy
2020https://dcmp.org/guides/TID7457.pdf
Activities”.
Access
May
28,
“Work and Energy”. Access May 28, 2020http://www.ncert.nic.in/ncerts/l/iesc111.pdf
“Kinetic
and
Potential
Energy”.
Access
June
http://phasesofmatter.weebly.com/kinetic--potential-energy.html
5,
2020
Answer Key
Activity 1:
1.
2.
3.
4.
5.
same
Kinetic
quadrupled
doubled
Mass and velocity
Activity 2:
A.
1. Truck
2. Because it has greater mass than other vehicles
3. Because the vehicles have different mass
B.
1. Car C
2. quadrupled or 4 times higher
3. because the 3 vehicles have different speed
Activity 3:
Given
Required
Mass = 1500 kg
Speed (v) = 5 m/s
KE
KE= mv2
2
Equation
Solution
KE = 1500kg (5 m/s)2
2
KE = 1500kg (100 m2/s2)
2
KE = 150, 000 kgm2/s2
2
Answer
KE = 75, 000 J